Work feed control



- March 29, 1932'. R. SCHNITZER IORK FEED CQITROL Filed Jan. 25. 1m

Patented Mar. 29, 1932 warren STATES PATENT ()FFHE RICHARD SCHNIIZER, OFZURICH, SWITZERLAND, ASSIGNOR TO A. G. BROVJN BOVERI & 0115., OF BADEN,SWITZERLAND, A JOINT-STOCK COMEANY WORK FEED CONTROL Application filedJanuary 25, 1926, Serial No. 83,481, and in Germany January 30, 1925.

This invention relates to a method and to apparatus for controlling theteed of work to a working element or to a plurality of working elements.

The general purpose of the invention is the automatic control of thework feed in such fashion as to maintain the load on the workingelement, or the respective working ele ments, substantially constant.

Another object is the provision of apparatus for effecting suchregulation, which will be relatively simple in construction, immedt ateand certain in operation, and positive in its effect.

Other and further objects of the invention Will be pointed outhereinafter, indicated in appended claims, or obvious to one skilled inthe art upon an understanding of the present disclosure.

In various types of machines, and particularly in machines designed forthe abrading, grinding or reduction of material, the work is fed to aworking element in the nature of a cutter or grinder which acts forciblyupon the work in a direction transversely to that in which the work isfed. This transverse force is transmitted thru the work and sustained bythe work holder which holds the Work to the action of the workingelement. The present invention provides for an arrangement of the workholder whereby at least a portion of it is movable to a varying degreeunder the transverse pressure transmitted to it from the working elementthrough the material in the work holder, and for any suitable regulatingmeans, responsive to such movement of the work holder, -tor varying therate or pressure at which the work is fed, or the'load upon the workingelement.

Forthe purpose of this application I show in the accompanying drawingsforming a part of this specification and described herein, certain formsof apparatus in which the invention may be embodied and practised, but

it is to be understood that these are presented for purpose ofillustrationonly, and are not to be accorded the effect of limiting theinvention claimed, short of its true and most comprehensive scope in theart. In the drawings Fig. 1 is a diagrammatic illustration in the natureof a sectional elevation of a wood pulp grinder illustrating anarrangement or the work holder or magazine in association with anelement of a regulating means.

Fig. 2 is a diagrammatic illustration showing in conventional fashion arelationship of regulating means with means for feeding the work to theworkin element or grinder. Fig. 3 is a diagrammatic illustration ofanother form of device for actuating the regulating means from themagazine or work holder of a wood pulp grinder; and

Fig. 4 is a diagrammatic illustration of a layout for the control of twoassociated grinders.

Th nature of the invention may be understood more in detail by referenceto these illustrative embodiments which, as stated above, show theinvention as applied to a machine for reducing wood to pulp for use inpaper manufacture or the like. In the portion illustrated in Fig. 1 letit be understood that numeral 10 designates the grinder or workingelement of the machine, to which the work is fed through the work holderor magazine 11. The grinder being driven in the direction indicated bythe arrow, it is obvious that it exerts a circumferential force againstthe material in the work holder, part of which force is consumed infriction and part transmitted through the material to the magazine in adirection tending to move the latter laterally. The magazine is somounted as to be susceptible of a moderate lateral movement in thedirection of the circumferential force exerted by the grinder and isrestrained against such movement by a spring 12. By an operatingconnection 14 such movement of the magazine is rendered efiective uponan element 15 of a regulating device arranged to control the feed of thematerial to the grinder. An arrangement of the regulating device and thefeed mechanism is illustrated in Fig. 2, wherein the latter is shown ascomprising chains 1t carrying flights or hooks which transmit the woodtowards the grinder, said chains being actuated by the motor 17 throughthe medium of driving connections 18. The speed of the (Work-feedingmotors l7 and 17 20, resultsin an increase of pensating adjustment motor17 is controlled by the regulating device 15. By virtue. of thearrangement, in the event the load imposed on the grinder increases tothe point Where the reaction,

transmitted through the Wood, is sufficient to move the magazine 11against t-heinfiuence of the spring 12, said movement of the magazine,transmitted through its operative connection With the re ulating deviceWill be effective to decrease the speed of the motor 17 and the rate orpressure at which thewood is fed to the grinder.-

ln Fig. 3 is illustrated a modified construction of operative connectionbetween the Work holdei and regulating device. In this form the portion11 ofthe Worn holder is movable and is effectively associated with.

the shaft end of the. bell-crank lever 16 by means of the knife edge 7.The bell-crank lever ispivoted at 16 and operatively con-.-

nected vith the control element 15 and arranged to oppose the resistanceof the spring 13 and adjustable Weight 18 to the movement ofthe-magazine portion 11, The dashpot 19 is provided to steady the actionof'the lever. i

In Fig. lis illustrated an arrangement for the regulation and uniformdistribution of the load to associatedgrinders I and II. -The Workingelements 10 and 10 of the respective grinders are driven conjointlybythe threephase motor 20, the respective Work holders ll and 11 havingoperative connection through their respective levers. 16 and 16' withregulators 21 and 21 which control the Which feed material to therespective grinders. These motors take theirsupply from the generator22, in VVa-rd Leonard connection. Generator 22 is coupled to the eXciterdynamo 24: which energizes the fields of the feed motors l7 and 17 andthe Ward Leonard generator22. The effectiveness of the generator 22 isrendered responsive to the load demand of the main I the totalload isuniformlydistributedbetweenthe Work grinders.

It will be appreciated that the application 'ofmy invention Willbeeflective to ncrease the total efiiciency of the Working apparatus ,bymaintaining the load substantially jcon- [stant at anr optimum value.lVhile Ihave .55 illustratedthe invention as employedfor the regulationof wood pulp grinders, it'is holder individi obvious that it issimilarly applicable to machines designed for various other particularpurposes.

What I claim is 1. Infeed-control apparatus of the character described,a working element, means for holding material for feeding to saidelement, said holding means being supported for moveinentdue ,tooccurring drag actionbetween the material and said element, means yieldingly restraining said holding means'agamst such movement, and meansresponsive to'conditions Whereat such drag action is sufficiently greatto overcome the-restraining action'of said restraining means and effectsuch movement of said holding means, said third-named means beingoperable upon occurrence ofsuch conditions to control'the rate of'feedof mate'- rial to said element.

' 2. Feed control apparatus comprising in combination, 'a movableWorking element, a material holder, means for feeding material into saidholderto be actedvupon by said element said holder bein movable resonsive 7 bp to action of said element upon said material ithin saidholder, and means responsive to movement of said holder to control saidfeed-. ingmeans.

. 3. Feed combination, a movable Working element, an electrical meansoperative to move said ele- 'ment, a material'holder, an electricalmeans operative to'feedmaterial into said holder to be acted upon bysaid'element, a control means for the last said electrical means andoperative to affect the same to vary the rate of the feeding of"material, into thesaid holder, the said holder being movable responsiveto actionof saidelement upon the material fed thereinto, and meansoperative responsive to movement of said holder to operate the saidcontrolimeans to a'fiect thelast said electrical means; l

a. "Feed 'controlepparatus comprising in combination, a plurality of'Workingelements,

anelectrical meanscommon to said'elem'ents and disposed to operatethesame, a material al to each of said plurality of elements, anelectrical means individual to each of said holders and operative'tofeed material into .the same to be acted upon by the associated one 'ofsaid elements, a control "means individual'to each of last saidelectrical means and operativeto-elfectthe same .to vary the rate ofthefeedingof'mat'erial' into the associated one of said'holders, eachcontrol apparatus compri'singin I ioo of said holders being, movableresponsive to action of the associated one of said elements 7 upon'thematerial therein, andmeans individual to each of said holdersandactuated re-' sponsive to "said movement thereof to actuate theSillClCOIltI'Ol means to affect the associated last said electricalmeans.

'5'. Feed control apparatus comprising in. 7 combinatiomarotatableWorking, element. an

electric motor operative to rotate the said element at varying rates ofspeed, a source of current supply for said motor, a material holder, anelectric motor operative to feed material into the said holder atvarying rates to be acted upon by said element, a dynamo electricmachine operative to supply operating current of varying potential tothe last said motor, means operative in dependence upon the supply ofcurrent from the first said source to the first said motor to vary thepotential of the current feed by the said generator to the last saidmotor to vary the speed of the latter, the said holder being movableresponsive to action of said element upon material fed into the saidholder responsive to operation of the said last said motor, and controlmeans operative responsive to said movement of said holder to afiect thesaid last said motor to vary the rate at which material is fed into thesaid holder.

In testimony whereof I have hereunto subscribed my name at Zurich,Switzerland, on the 11th day of January, A. D. 1926.

RICHARD SCHNITZER.

